Bioactivity Potential of Cyanobacterial Species Inhabitant of Southwestern India

Abstract

Cyanobacteria possess potent bioactive compounds of nutritional and medicinal significance. This study evaluates the antioxidant compounds, antioxidant enzymes, and antioxidant potentials of 12 cyanobacterial species isolated from different unpolluted and polluted ecosystems (lentic water, reservoir, thermal spring, dairy effluents, domestic sewage effluents, pharmaceutical effluents, and iron ore mine effluents). The top producers of antioxidant compounds (total phenolics, flavonoids, tannins, and reduced glutathione), vitamins (C and E), and enzymes (catalase, glutathione peroxidase, glutathione reductase, glutathione S-reductase, and superoxide dismutase) showed a high antioxidant potential (total antioxidant activity, DPPH radical-scavenging activity, nitric oxide-scavenging activity, and ferric-reducing power). Methanol extracts possess consistently higher quantities of total phenolics, flavonoids, and tannins and antioxidant activities than ethanol extracts. Among the 12 species, Leptolyngbya fragilis, Phormidium corium, and Planktolyngbya limnetica were common among the top 5–6 species. The quantities of reduced glutathione, catalase, and superoxide dismutase of these species showed a strong positive correlation with all the antioxidant activities assessed, justifying their effective protective roles by their antioxidant potential. This study recommends three cyanobacteria (L. fragilis, Ph. corium, and Pl. limnetica) based on their antioxidant compounds, antioxidant enzymes, and antioxidant activities for future progress in cyanobacterial biotechnology.